Oracle on Wednesday issued a critical patch update for Java SE. The bulletin offers 42 new vulnerability fixes. A whopping 39 of them may be remotely exploitable without user authentication. But this month, it's launch of a new malicious-app warning system that's drawing the most criticism.

Let's review the Java drama, or at least part of it. In just 30 days, Oracle has pushed out three updates to fix critical vulnerabilities in Java -- and the last update was an emergency fix. The company is still working to manage the latest crisis with Java 6.

"This update addresses the vulnerabilities found during the PWN2OWN competition at CanSecWest in Vancouver in March, where Java was exploited by three different security researchers," Wolfgang Kandek, CTO of Qualys, told us. "Oracle also changed the alerts that come up when one runs a Java applet, introducing distinct states giving overall more information on the nature of the applet. The new versions are update 21 for Java version 7 and update 45 for Java version 6."

Warnings About Java Applets

But the update is mostly the same old, same old. What's new is the way the Java browser plug-in behaves. The Java 7 Update 21 changes the plug-in behavior that is supposed to help you make more informed choices before running the Java applet in the browser.

Here's how it works: a security prompt asks for a confirmation before allowing Java content to run in the browser. Oracle said the messages presented depends upon different risk factors, such as using old versions of Java or running applet code that is not signed from a trusted Certificate Authority.

"Apps that present a lower risk display a simple informational message," Oracle said in its Java blog. "This includes an option to prevent showing similar messages for apps from the same publisher in the future."

Java ran through several scenarios of the types of messages -- which include various icons and color coding to explain the risks -- that users may receive and what they mean in practice. Oracle offers screen shots of each scenario, and there are many different possibilities that could appear.

A Confusing Update

Paul Ducklin, a senior security analyst at Sophos, isn't thrilled with the update. He pointed to the numerous combinations of alerts and warnings and said that although Oracle has offered careful explanations of each one, the security ball remains very much in the users' court.

"Logo and shield. Triangle and shield. Shield alone. Triangle alone. Confused yet? You're forgiven if you are, because these dialogs end up asking the very questions that you might reasonably expect Java to answer," Ducklin wrote in a blog post.

"Many users will therefore understandably be tempted to rely on the "Do not show this again" option to deal with these alerts. A better solution, unless you need Java in your browser, and know you need it, is simply to turn it off."